From July 2011, the ABS will be replacing the nation's official statistical geography, the Australian Standard Geographical Classification (ASGC) with the new Australian Statistical Geography Standard (ASGS). The ASGS will define more stable, consistent and meaningful areas than the ASGC and will become the essential reference for understanding and interpreting the geographical context of ABS statistics. Current ASGC regions such as Census Collection Districts (CCDs), Statistical Local Areas (SLAs) and Statistical Divisions (SDs) will be replaced by the new Statistical Levels 1 to 4 (SA1 - SA4). For more information about the ASGS, including maps, labels and codes, see Australian Statistical Geography Standard (ASGS): Volume 1 - Main Structure and Greater Capital City Statistical Areas, July 2011 (cat. no. 1270.0.55.001).

POPULATION ESTIMATES UNDER THE ASGS

From 2011 onwards, the SA2 will be the base spatial unit used to prepare and disseminate sub-state population estimates.

The first set of population estimates under the ASGS will be prepared for 30 June 2011 and released around July 2012 in Regional Population Growth, Australia (cat. no. 3218.0). This release will contain a time series of estimates for the new geography, as well as estimates based on the old geography. Sub-state population estimates for 30 June 2012 and onwards will only be prepared and released based on the ASGS.

As LGA population estimates are regarded as a crucial ABS output, they will continue to be prepared post 2011. The boundaries on which these LGA estimates will be prepared will be updated each year, in line with official gazetted boundaries for all LGAs.

Sub-state population estimates by age and sex will also continue to be prepared and released under the new geography. Estimates will be prepared at the new SA2 level by single year of age and sex, but will be released on the website in five-year age groups, in Population by Age and Sex, Regions of Australia (cat. no. 3235.0). The first set of sub-state age and sex estimates under the ASGS will be released in August 2012.

The SA2 population estimates will be broken down into SA1s, which can then be aggregated to form non-ABS structures (Postal Areas, State Suburbs, State Electoral Divisions, Remoteness Areas etc) which make up part of the ASGS. These estimates will generally not be released on the website, however will be available on request.

The change in geographic classification means there will be an unavoidable break in time series. To assist users with this break in time series, the ABS plans to prepare historical population estimates under the new geography. The length of the time series will depend on the geographic level and the type of estimate. For larger areas (e.g. capital cities) the ABS is aiming to prepare longer time series. Time series will be released as part of the first releases of ASGS population estimates in July/August 2012. The ABS is aiming to release more details in an information paper around mid 2011, which will be linked to this product.

A set of correspondences (concordances) will also be available to assist users in converting data from one geography to another. For a list of correspondences that the ABS intends to release please see the Frequently Asked Questions link in the ABS Geography Portal.